The present invention relates to an arrangement for transporting bulk materials, and more particularly to a reversible bulk conveyor arrangement.
There are already known various conveying arrangements of the type here under consideration which, generally speaking, are used for conveying loose particulate or bulk material from one location to another. Such arrangements usually have a plurality of buckets mounted on a bucket wheel which rotates about a horizontal axis while the machine on which the bucket wheel is mounted advances so that the bulk material seriatim enters the buckets through their open ends and is subsequently discharged therefrom at a distant location. Some of these conventional conveying arrangements are reversible which means that not only the rotation of the bucket wheel can be reversed, but also the buckets which are mounted on the bucket wheel must be displaceable between different end positions in each of which the open end of the bucket faces in a different circumferential direction of the bucket wheel. It will be appreciated that, when the conveying arrangement is of the reversible type, the bulk material can be transported by the buckets regardless of the direction of advancement of the machine which carries the bucket wheel.
Such reversible bucket conveying arrangements can be, for instance, used for turning over a heap of bulk material, such as coal or ores in which layers of different particle magnitudes have been formed during the original formation of the heap. As a result of the fact that the bucket wheel rotates about a horizontal axis, it simultaneously removes the bulk material of different particle magnitudes from the various horizontal layers of the heap, which improves the homogeneity of the heap of the particulate material which is formed downstream of the bucket conveying arrangement. The original lack of homogeneity, and the existence of the layers of different particle magnitudes, result from the fact that the material which is to be deposited in horizontal layers to form the heap passes through a comminuting device prior to being deposited, which comminuting device comminutes the material to particles of different magnitudes or sizes depending on the hardness and coherence of the larger particles to be comminuted. The present invention is concerned with a bucket conveying arrangement of this type, but it will be appreciated that the concepts of the present invention can also be used in conveying arrangements of different types.
As already mentioned above, in order to improve the efficiency of the conveying arrangement by operating the transporting arrangement not only during the forward advancement of the device on which the bucket wheel is mounted, but also during the rearward advancement, it is already known to reverse the rotation of the bucket wheel and to angularly displace the buckets so that the open ends of the buckets face in an opposite circumferential direction of rotation of the bucket wheel. For this purpose, it is already known to mount the buckets on the bucket wheel for pivoting between their end positions about pivot axes parallel to the axis of rotation of the bucket wheel. This operation is usually performed manually, one bucket after the other. This involves a laborious, expensive, and even dangerous operation which includes serial release of arresting means which holds the respective bucket in one of the end positions, tilting of the bucket about the pivot axis, and rearresting the bucket in its other end position. The conventional arresting means used for arresting the buckets in their end positions includes screws, wedges and similar arresting means. Thus, it will be seen that the serial tilting of the buckets is very time-consuming, requires exertion of substantial forces, particularly when the buckets are heavy, and the need for the presence of the operating personnel in the vicinity of the bucket wheel involves a certain amount of danger.